In a manufacturing process for an electronic component such as an IC device, a testing apparatus is required for testing the electronic component which is finally manufactured. An apparatus for testing a plurality of IC devices at one time under higher temperature conditions than normal temperature (thermal stress conditions) is known as one type of such a testing apparatus.
In this testing apparatus, a test chamber is formed in the upper portion of a test head, and while the interior of the test chamber is controlled to a predetermined set temperature using air, a test tray supporting a plurality of IC devices which have been similarly preheated to the predetermined set temperature is transported to a socket on the test head. A test is then performed using a pusher to push the IC devices into the socket and connect the IC devices. By means of such a test performed under thermal stress, IC devices are tested and sorted into at least good and defective products.
However, in the aforementioned test chamber, heat escapes from the outer walls or the socket, and as a result the temperature of the pusher which is on standby near the center of the test chamber rises beyond the set temperature, whereas the temperature of the socket falls below the set temperature. If an IC device which has been preheated to a predetermined set temperature is pushed into the socket by the pusher in these conditions, the IC device is affected by the pusher, which has a higher temperature than the set temperature, such that the temperature thereof initially rises, and is then affected by the socket, which has a lower temperature than the set temperature, such that the temperature thereof falls. If the IC device is of a type which generates heat itself during operations (during a test), then the temperature of the IC device may rise even further above the set temperature during the test.
When the temperature of an IC device diverges so greatly from the set temperature, it is impossible to perform an accurate test on the IC device. For example, if a test is performed on an IC device at a much lower temperature than the set temperature, defective products may be judged to be good products, and if a test is performed on an IC device at a much higher temperature than the set temperature, good products are judged to be defective products such that yield deteriorates.
Configurations for controlling the temperature of an IC device by interposing a heater between a pusher serving as a heat sink and an IC device have been disclosed (U.S. Pat. No. 5,821,505, No. 5,844,208, and No. 5,864,176). In order to generate a cooling effect in the heat sink in such configurations, the thermal resistance between the IC device and the heat sink, or in other words the thermal resistance between the IC device and heater and between the heater and heat sink must be reduced, but in so doing, when the IC device is heated by the heater, the heat sink is also heated, and thus when attempts are made to cool the IC device, the IC device cannot be effectively cooled since the heat sink is warm.